Vibrator or like apparatus operating on elastic fluid



Nov. 9, 1965 A. H. PETERSON VIBRATOR OR LIKE APPARATUS OPERATING ON ELASTIC FLUID 5 Sheets-Sheet 1 Filed Oct. 24, 1965 FIG O 8 8 2 8 a Q A. 41% 7 6 3 4 a o 2 9 6 9 8 7 6 7 \T I I 6 8 8 F w 3 II 6 IE 0 8 H 4 \VA 4 7 3/ J: 2 6 8 9 0 ll 2 8 4 INVENTOR. A. H. PETERSON ATTORNEY Nov. 9, 1965 A. H. PETERSON VIBRATOR OR LIKE APPARATUS OPERATING ON ELASTIC FLUID 5 Sheets-Sheet 2 Filed Oct. 24, 1965 INVENTOR. A. H, PETERSON AYTORNEY United States Patent 3,216,328 VIBRATOR 0R LIKE APPARATUS OPERATING 0N ELASTIC FLUID Axel H. Peterson, 4431 5th Ave., Rock Island, Ill. Filed Oct. 24, 1963, Ser. No. 318,638 22 Claims. (Cl. 9152) This invention relates to a force-applying apparatus and more particularly to that type of apparatus in which the force is derived from elastic fluid such as compressed air and is converted to mechanical forces for use in mechanisms having energy-conversion means employed for vibrating, shaking, pounding, punching, impacting etc. More particularly, the invention relates to improvements in devices for regulating the admission of elastic fluid pressure in explosive bursts as distinguished from virtually non-compressible fluids such as oil, etc.

Exemplary of this general type of apparatus is that forming the subject matter of co-pending application Serial No. 405,953, filed Oct. 23, 1964, as a continuation of now-abandoned Serial No. 177,949, filed March 5, 1962, in which energy-conversion means in the form of a hammer or weight is carried in a cage or equivalent support for reciprocation toward and away from, for example, a plate which may be attached to an object to be vibrated, such as a load-carrying container in which the vibratory forces imparted to the container facilitate unloading. In the absence of the striker plate, the cage or hammer support may be attached directly to such container or other object, or the hammer or weight may be used for punching, pile driving etc. In still other instances, the hammer need not strike the striker plate or its equivalent but the reciprocatory motion developed may be utilized without the impact. In the example referred to, the hammer cage is divided or separated from an inlet accumulator chamber by a partition having an opening therein with which a valve cooperates for the intermittent admission of air to piston means associated with the hammer and operating in an expansive or power chamber. Each time air or equivalent fluid pressure is introduced to the piston means, the hammer moves away from the partition on what may be regarded as a power stroke. Depending upon the position and location of the apparatus, the hammer has a return stroke on which it is biased, either by its own weight or by other biasing means. The arrangement in the prior art is such that the hammer on its return stroke directly or immediately engages and opens the valve to admit another charge of pressure to the piston. As the hammer moves on its power stroke, the valve automatically closes, and other discharge means are provided for discharging the piston so that the hammer may return.

Since, in the prior apparatus just referred to, operation of the valve is directly dependent upon the return of the hammer, the return stroke of the hammer must be specially accommodated; e.g., the bias force behind the hammer must be great enough not only to return the hammer but also to open the valve. Where such biasing forces rely on springs, the springs must be large and these in turn introduce cost and space complications. Furthermore, the valve must be relatively close to the hammer to avoid intricate mechanical connections and this virtually precludes remote control of the valve. In other prior art devices of the general type referred to, only relatively high speeds are obtainable, roughly in the order of, say, two thousand to ten thousand vibrations per minute. In the copending application, much lower speeds can be obtained, but according to the present invention, still lower speeds are obtainable by a completely different valve arrangement, and speeds in the range of 3,216,328 Patented Nov. 9, 1965 five hundred blows per minute down to one blow per two or three minutes can be achieved.

It is therefore a principal object of the present invention to provide an improved valve system and control therefor. The improved system features opening of the valve by inlet chamber pressure entirely independent of hammer position, controlling the valve in such fashion that the frequency of its action is varied by the rate of exhaust from a counteracting chamber acting in opposi tion to the opening force of the inlet pressure or rate at which the inlet chamber is charged. The invention features a valve system in which opening of the valve occurs rapidly and widely, thus avoiding cracking or creeping of the valve. It is a significant object of the invention to utilize in the control means the application of pressure to pressure-receivable areas so related to the valve movement phases that simple releasable elements may be used to close and retain the valve closed until the pressure rise in the inlet chamber is sufficient to overcome the holding force. Specifically, it is a feature of the invention to use magnetic elements for applying at least part of the valve-closing forces.

A still further object of the invention resides in a construction in which the valve structure and control therefor may be readily incorporated in a unit that is easily installed and removed from the basic supporting structure.

It is a further object of the invention to exploit these principles in a commercially successful device capable of developing relatively high forces, viz, in the range of twenty to thirty-five foot pounds on as little as 40 p.s.i. Such apparatus, using air at as low as one-half to five cubic feet per minute, may be operated by a fractional horsepower compressor.

A further object is to incorporate in such apparatus the characteristics of strength, ruggedness and portability; e.g., in weight ranges of from 25l00 l-bs. so that it may be eaosily handled by one man as it is moved from job to jo- The foregoing and other important objects and desirable features inherent in and encompassed by the invention will become apparent as preferred embodiments thereof are disclosed in detail in the ensuing description and accompanying sheets of drawings, the figures of which are described below.

FIGURE 1 is a sectional view, with portions in section contained in two planes intersecting at the axis of the apparatus of one form of the invention, with a source of fluid pressure and associated lines shown schematically.

FIGURE 2 is a section as seen generally on the line 2-2 of FIGURE 1.

FIGURE 3 is a fragmentary sectional view of a center portion of FIGURE 1, showing the valve in its open position.

FIGURE 4 is a section similar to FIG. 1 but showing a different form of the apparatus.

FIGURE 5 is a section also similar to FIG. 1 but showing a modified construction.

FIGURE 6 is a fragmentary sectional view showing a further modified form of construction.

FIGS. 1-3: Description In this form of the invention, the vibrator as a whole may be regarded, by way of example, as comprising a casing 10 made up basically of three coaxial parts 12, 14 and 16 rigidly but removably joined together by a circle of cap screws 18, parts 12 and 16 being appropriately flanged to sandwich between them the marginal portion of part 14. In the illustrated use-environment, the unit is suspended from a typical object to be vibrated (represented at 20) and hence part 12 is uppermost; but, as

will be clear from what ensues herein, this position does not exclude others.

The unit may be removably attached to such object by an attaching flange 22, apertured to receive a circle of bolts 24 including cushion springs 26.

Part 12, which may be a casting, forms a cage or support 28 within which energy-conversion means such as a hammer or its equivalent mass 30 is reciprocable on alternate strokes (here vertical) between upper and lower limits such as, respectively, the under surface 32 of object 20 and the opposed surface 34 of central part 14, which here serves as a partition between parts 12 and 16. That portion of cage 28 between hammer 3t) and partition 14 establishes a power cylinder or expansive chamber 36, shown contracted in FIG. 1 because the hammer is down but capable of expansion as the hammer moves up. The bottom end of the hammer is thus a movable wall or piston means 38 acting on or in conjunction with the hammer. The top end of cage 28 is vented at 40 to avoid trapping air behind the hammer as the hammer, slidably fitting the interior wall or cylinder of the cage, reciprocates without the benefit of seals and depends for lubrication on lubricant entrained in the elastic fluid, hereinafter sometimes called simply compressed air. As will be explained subsequently, a sealed piston and hammer may be utilized. For the present, the presence or absence of a seal may be temporarily ignored. I

As the hammer moves by gravity bias from an upward position toward that shown in FIG. 1, air must be discharged from the chamber 36, preferably by some means other than relying on leakage between the piston and cage 28. In the first place, this leakage is normally too small, it is irregular and it cannot be positively controlled. Therefore, a controlled discharge is provided, here by passage means 42 through the wall of the cage and equipped with a variable orifice, efiectuated here by a cock 44. Hence, the piston-cage leak can be disregarded, as further evidenced by the absence of a special seal between parts 12 and 14, whereas a seal 46 (here a typical ring) is used between parts 14 and 16, because the inlet chamber 48 within the part 16 cannot reconcile leakage and eflicient operation.

Inlet chamber 48 is constantly pressurized by an inlet line 50 which may be connected by a valve 52 to a source of elastic fluid (e.g., compressed air) such as a compressor, shown schematically at 54, or to a compressed air line (not shown) such as are available, generally at 100 p.s.i., in most industrial plants, etc. Valve 52 may be any well known flow control valve which functions to bleed the air into inlet chamber 48, or it may be a conventional pressure regulator valve which allows the air to flow into the chamber 48 at a rate determined by the valves capacity, the flow stopping when inlet chamber pressure reaches a predetermined pressure (the pre-set maximum of the regulator valve).

Transmission of fluid pressure from inlet chamber 48 to power chamber 36, and control thereof, is achieved by means including the part or plate 14 and a port 56 therein, shown here as circular and centrally located, by way of example. Broadly the geography of the port and its allied components could be otherwise than as shown.

The central underside of plate 14 within inlet chamber 48 has an integral circular depending cup 58 provided with circumferentially spaced openings 60 communicating chamber 48 with the interior of the cup. The rim of this cup coaxially mounts a valve support or housing 62 via cap screws 64, and this housing has therein a valve bore 66 coaxial with port 56. A valve 68 is axially slidably carried in this bore and projects at one end (here its top end) through the open or port-proximate end of housing 62, being provided thereat with a reduced cylindrical port-control portion 70 and an enlarged annular flange 72. The lesser diameter of portion 70 as respects the main body of the valve afiords a first pressure-receivable area 74 (the larger diameter of flange 72 is immaterial, since both faces of the flange are exposed to inlet chamber 48). The diameter of portion 70 and the amount of axial movement of the valve are such that said portion slightly enters the port in the port-closing position of the valve (FIG. 1) and is withdrawn from the port in the port-opening position of the valve (FIG. 3). This portion 70 is supplemented by an annular seal 76, here a conventional O ring, to perfect closing of the port Without expensive lapping of metal surfaces.

Magnetic means, here a circle of separate magnets 78 mounted on the underside of plate 14 by screws 80, attracts the valve to its closed position via metallic flange 72. This attractive force is somewhat less than the force on area 74 at predetermined pressure in inlet chamber 48 when valve chamber 84 is at atmosphere. Thus, when the valve is closed (FIG. 1) and held there by the magnetic means, chamber pressure force on area 74 will have to exceed the magnetic force, plus other forces to be noted later, in order to open the valve (FIG. 2). This can be termed the value of the predetermined force. These forces can be readily calculated for devices of different sizes, capacities and rates of operation, and to be taken into account are such things as frictional drag of O-ring seal 76, friction between valve 68 and valve bore 66 and frictional drag of another seal 82, here also an O ring, between the valve and the bore, besides strength of magnets, amount of valve opening etc.

Seal 82 operates as means isolating the lower interior of the valve bore, designated as a valve chamber 84, from inlet chamber 48 when valve 68 is closed. In short, when the valve closes port 56, both power chamber 36 and valve chamber 84 are cut off from inlet chamber pressure, the rise of which becomes effective, when the magnetic force is overcome, to open the valve, allowing a rush of air through the port and into power chamber 36 to force the piston and hammer upwardly or away from partition plate 14, which phase of operation is not alfected by discharge passage 42-44 or by leakage past piston 38.

Now, with the hammer up and valve 68 open via inlet chamber pressure acting on pressure area 74, it remains to reclose the valve to cut off air to the power chamber so that the piston-hammer may return as power chamber air is discharged via passage 42-44. To accomplish this requires that some means be provided to return the valve automatically to closed position; that is, with out, for example, closing line valve 52.

This is achieved, by counteracting at least part of the valve-opening force by an opposing force so as to effectuate the magnets as an ultimate valve-closing means. Briefly, what is done is to lead inlet chamber pressure to valve chamber 84 where it will act on a second pressure-receiving area 86 at the end of the valve opposite to the first area 74. It will be appreciated that when valve 68 is open, the whole upper end thereof is then acted on by inlet chamber pressure; and in eifect the whole lower end 86 is exposed to valve chamber 84. I

Valve 68 has here an axial through passage 88 opening at valve end 70 and made up of a series of counterbores including a relatively large bore 90 which opens at valve end 86 and thus to valve chamber 84, but this passage is effective only when valve 68 is open, for when the valve is closed (FIG. 1), passage 88 is cut off from the inlet chamber.

Valve chamber 84, in addition to being connectiblevia passage 88 to inlet chamber 48 (when valve 68 is open, FIG. 3), is vented to a lower pressure than inlet chamber pressure, e.g., atmosphere, by an outer annular groove 92v in valve 68, a radial bore 94 in the valve which leads:

from groove 92 to valve bore 91! and thus to passage: 88, and a radial passage 96 in valve housing 62" which is always in register with groove 92 p FIGS. 1 and 3 and which leads to atmos her ia a series of connected passage portions 98, 100 and 102, a needle valve 104 and alined bores providing an outlet 106. Needle valve 104 is a means for regulating the vent passage and cock 40 is another means for regulating power chamber discharge passage 42. The specific passage arrangement is deemed to be novel as to the use of the central valve passage 88-90 for the dual use described; although, the equivalent of that system is regarded as broadly novel irrespective of details.

In keeping with adequate sealing of the inlet chamber while valve 68 is closed, a seal at 108 is provided at the junction of passages 98 and 100. A plug 110 is shown as closing the outer end of passage 96 after drilling.

Valve bore 90 is shown as containing a coaxial coiled spring 112 acting between the valve and the closed end of valve housnig 62. Although not absolutely necessary, such spring has practical advantages in supplementing the magnetic means, such as overcoming the break away resistance of the O ring 82, enabling the use of magnets of smaller force, and serving as a cushion against extreme valve-opening movement.

A check valve 114 normally closes passage 88 at the shoulder formed by the junction of that passage with valve bore 90, being biased to closed position by a relatively light coil spring 116 disposed loosely within valve spring 112 and acting between the check valve and the closed end of valve housing 62.

Operation: FIGS. 1-3

The starting positions of the parts can be those shown in FIG. 1. Line presusre via 545250 builds up in inlet chamber 48 to the pre-set amount; e.g., 30 p.s.i.g., while valve chamber 84 is vented to atmosphere via 90 etc. as regulated by needle valve 104. Passage 42, controlled by cock 40, has a lesser restriction to fluid flow than outlet 106 as afi'ected by needle valve 104. Inlet chamber 48 is sealed against leakage by seals 46, 76, 82 and 108, valve seal 82 isolating valve chamber 84 from the inlet chamber and port seal 76 isolating power chamber 36 from the inlet chamber. Pressure rise in inlet chamber 48 acts thus against pressure area 74 on valve 68 until it overcomes the attractive or holding force of magnets 78 plus springs 112 and 114 which force is, say, twenty-one pounds as against a pressure area at 74 of, say, 700 square inches, in which case the valve will quickly open at 31 p.s.i. in the inlet chamber, give or take a pound or two because of frictional drag and other small variables. The rapidity of valve opening occurs because as flange 72 breaks away from magnets 74, the magnetic attraction deteriorates. This predetermined pressure becomes the minimum pressure at which the valve will open when the valve chamber is at atmosphere.

The valving intervals are here determined by the speed at which the effect of inlet pressure on area 74 builds up to the preset value via the flow control valve. The needle valve 104 is adjusted to assure discharge of the valve chamber 84 prior to next build-up and yet allows a pressure rise in the valve chamber on the power cycle to close the valve.

When valve 68 opens, inlet chamber pressure rushes into power chamber 36, acting much as an explosive burst on piston 38 to drive hammer 30 upwardly. Whether or not the hammer strikes surface 32 of object 20, a relatively powerful impulse will result, jarring the object or applying other desired force to an equivalent object. Although the discharge passage 42-44 is so restricted relative to the charge of air bursting into power chamber 36 as to have no material effect thereon, adjustment of this passage by cock 44 will determine the rate of return of the hammer. The hammer should reach or substantially reach its return limit (surface 34) before valve 68 re-open after closing following its opening action just described.

Valve 68 closes because of force developed in valve chamber 84 to counteract the valve opening force, which 6 will be clear by recognizing that when valve 68 opens it exposes its lower end 70, and thus its passage 88, to inlet chamber pressure which easily opens check valve 114 and enters valve chamber 84 to act against valve area 86, and the check valve closes as, ultimately, substantially balancing forces occur against both ends of the valve at inlet chamber pressure. The valve is then conditioned to again come under the attractive influence of the magnets. The expression substantially balancing" is used here as one of convenience, because exactly equal forces need and may not occur at opposite ends of the valve. For example, the attractive force of the magnets could take effect prior to exact equalization. Also, when valve 68 opensport 56, there will be a pressure drop in the inlet chamber. Factors such as this reveal convenient measures for varying the speed of valve closing by varying the rate or time of equalization, as by judiciously proportioning the diameter of passage 88.

In this instance, the magnets are assisted by the springs 112 and 116; although, it will be clear that stronger magnets could eliminate the spring 112 (the spring 116 has negligible force in this phase) so far as forces are concerned. Stronger magnets will enable greater valve opening, since their power of attraction is greater and they will have greater reac for the valve. The spring 112, however, has at least three distinct advantages: First, it overcomes frictional drag between valve 68 and housing 62 as well as overcoming breakaway resistance of seal 82. Second, it serves as a cushion or bumper for the valve during valve opening and avoids direct contact between valve flange 72 and the proximate marginal portion of valve housing 62 (note space 118 in FIG. 3). Third, spring 112 permits use of weaker magnets and gives the valve an initial push within the attractive reach of the magnets so that the magnets complete the valve-closing action. (Another form of the invention will be covered below wherein a valve spring such as spring 112 can be adjusted.)

One feature of the O ring 76 on valve portion 70 will become apparent: Since the O-ring can partially enter port 56 while closing same, the height of the magnets need not be so carefully controlled so long as the magnets stop valve flange 72 after (not before) the O ring enters the port. That is to say, the valve may have limited overtravel but no undertravel on closing, but overtravel is more easily accommodated by the control disclosed here. Overtravel, however, should not be excessive, since it merely adds frictional drag. It is preferred that port 56 have a slight countersink around its bottom edge as shown. This avoids one disadvantage of a poppet valve with conical seating surfaces, which allow for no such overt-ravel.

Now, with valve 68 closed, there again occurs the isolation of chambers 48, 36 and 84 from one another. Air let into chamber 84 when the valve opens ultimately vents off via the passage 94 etc. to outlet 106. Air from power chamber 36 finds an easier exit via passage 42 and cock 44 and will therefore not open check valve 114. The rates of discharge of the two chambers 36 and 84 may be independently controlled by cock 44 and needle valve 104 respectively. (A form of the invention without the check valve 114 and using the valve chamber vent passage for discharging the power chamber will be described subsequently herein.)

In FIGS. 1-3, the power chamber discharge passage 42-44 may be controlled, whereas discharge via leakage past the piston 38 cannot. Further, as already stated, passages 42-44 and 94104 can be regulated independently of each other, since check valve 114 separates the two.

It will be clear that valve 68 closes rapidly because of the magnets, once the pressures are balanced. The time interval preceding re-opening will depend upon pressure build-up in the inlet chamber versus rate of discharge of valve chamber 84, and this in turn depends upon the setting of needle valve 104, which will follow from the observation that, if the needle valve is fully closed immediately following closing of valve 68, air trapped in valve chamber 84 would prevent valve 68 from opening- It will be seen that higher pressures can be introduced into the inlet chamber 48, via the pressure regulator 52,. than the preset minimum or amount and the intervals can be controlled by dropping the pressure in valve chamber 84 without returning it to atmosphere, for it is the relation of inlet to valve chamber pressure that allows the valve to open and not necessarily the relation to atmosphere. It should be recalled that when the flow valve is: used the needle valve is not critical and the intervals are controlled by the rate at which the inlet chamber rises to the preset tripping pressure. When the pressure regulator is use-d the air is dumped into the inlet chamber and the control is had by the rate at which the valve chamber is discharged. When the regulator is used any pressure above the preset minimum can be used, for the valve chamber is then discharged to a pressure approximately 30 p.s.i. lower than the inlet pressure. 30 p.s.i. is used as an example, for the preset pressure can be any one desired by choosing the relationship of the magnet strength to the area 74.

By way of preliminary summary, it has been shown that regulation of a device capable of developing forces up tothirty-five foot pounds can be achieved to produce a. range of impulses from 500 per minute down to one per two or three minutes. Regulation is accomplished by variation and adjustments of needle valve 104, cock 44, passage 88, strength of magnets 78 in relation to area 74, etc. A system employing check valve 114 is desirable where valve 52 is a pressure regulator and where no seal is provided between piston 38 and power chamber 36. Omission of the check valve when used with a pressure regulator at 52 would preclude desirable low-speed operation in most conditions.

The foregoing are features of FIGS. 1-3. Other features, usable alone or with those of FIGS. 1-3, will be developed below.

FIG. 4; Description The basic features of construction of FIGS. 1-3 are repeated here, with certain differences to be pointed out as the description proceeds. Where fundamental sim iliary exists, accompanied by structural differences, reference numerals employed in FIGS. 1-3 will be used with the sufiix a, and uneven numerals will designate further structure.

The FIG. 4 design has the apparatus a made up of parts 12a, 14a, and 16a, the latter two forming inlet chamber 48a and part 12a providing cage 28a in which hammer 30a is reciprocatable. Here, however, the parts are reversed as to FIG. 1, i.e., inlet chamber 48a is above and power chamber 36a is below, which requires that hammer 30a be biased upwardly, as by a spring 31, away from lower limit 32a on object a and back toward upper limit 34a. A further difference here is that inlet and power chambers 48a and 36a are or can be relatively remote from each other, depending upon the length of fluid line or conduit 17 that extends between passages 13 and 15 respectively in parts 12 and 14. In this respect, however, passages 13 and 15 and conduit 17 are regarded as but an extension of the power chamber, since passage 13 is part of 36a and 15 leads to port 56a, which is controlled by valve 68a in valve housing 62a carried by parts 14a and 16a. In other words, the lower portion of part 14a, in which port 56a occurs, along with passage 15, conduit 17 and passage 13 affords the fluid pressure transmission means which is the broad equivalent of FIG. 1. inlet chambers may be located remotely from each other. That portion of the apparatus comprising the parts 14a and 16a as united by cap screws 18a is shown as being affixed to a support by bolts and an attaching leg 27.

Valve 68a is substantially identical to valve 68 as to port control portion 70a, seals 76:; and 82a, flange 72a,

One advantage of FIG. 4 is that the power and to differently orificed :plugs like 104a.

pressure areas 74a and 86a; valve support 62a has a valve chamber 84a enclosing valve area 86a and carries a spring 112a, but in this case the force of the spring can be varied by an adjusting screw 113; and magnets 78a operate on valve flange 72a as before.

Another difference from FIG. 1 occurs in the location of passage 88a in a wall of part 14a rather than in valve 68a. This passage has a check valve 114a loaded by spring 116a in counterbore 94a which leads via passage 96a to a restricted-outlet 106a provided in a drilled plug 104a rather than via a needle valve as at 104 in FIG. 1. Passage a from valve chamber 84a intersects passage 96a and thus also leads to outlet 106a. Variation of valve chamber discharge can be obtained however by changing This adjustment is of course in addition to and independent of the power chamber discharge via passage 42a and cock 44a.

Passage 8801 leads to power chamber extension 15 and thus is closed to inlet chamber 48a when valve 68a is closed but is open to the inlet chamber pressure when the valve is open, as in FIG. 1. Check valve 114a has the same function as check valve 114 of FIG. 1. Line pressure is supplied by means of components 50, 52 and 54, which are the same as in FIG. 1.

Operation: FIG. 4

In general, operation follows that of FIG. 1. Inlet chamber 48a is charged from line 50 until pressure rise acting on valve area opens valve 68a and the burst or rush of air to power chamber 15-17-13-36a forces pistonhammer unit down. Inlet chamber pressure rise in passage 15 lifts check valve 114a and is applied to upper valve area 86a via passage means 94a, 96a and 90a and valve chamber 84a, counteracting the valve opening force until the valve is closed by magnetic means 7 8a. In this case, piston-hammer unit moves on its return stroke because of return spring 31 but the action is the same, power chamber 36a etc. being discharged at 42a-44a rather than opening check valve 114a (now closed as inlet and valve chamber pressures equalize). Adjustment of screw 113 enables variation of spring load on valve 168a to change the amount of inlet chamber pressure required to open valve 68a; e.g., increasing load on spring 112a increases inlet chamber pressure necessary to overcome magnets plus spring. Spring 112a serves also the cushion or bumper function of spring 112. Other functional characteristics of FIG. 1 will be readily recognized and need not be elaborated.

FIG. 5: Description This form of the invention is identical to FIG. 1 ex cept that check valve 114 and its spring 116 are omitted, as are power chamber discharge passage 42 and cock 44, and the hammer piston is provided with a seal. In the interests of clarity, certain of the reference numerals used in FIG. 1 will be repeated, sutficed by the letter b. Thus, the apparatus 106 has a hammer cage 28b and inlet chamber 48b, the latter being charged by line pressure at 54-52-50 to open valve 63b and charge power chamber 36b, piston 38b acting to move hammer 30b away from limit 34b toward limit 32b on object 20b to which the apparatus is attached by bolts 24b and cushion springs 26b.

Valve 68b is carried by valve housing 62b and is controlled by magnets 78b and flange 72b and valve chamber 84b in conjunction with valve areas 74b and 86b. Valve passage 88b opens for valve port-control portion 70b directly to valve spring bore 90 without a check valve, and spring 112b operates as spring 112 does in FIG. 1. Passages 92b, 94b, 96b, 98b, 1011b and 102b lead valve chamber 84b and passage 88b to outlet 10611, which is controlled by needle valve 104b.

Since piston 38b is sealed, as by O ring 39, no air leakage will occur between the piston and cage or cylinder 28. Without a check valve, such as 114, in passage 88b, power chamber discharge will occur via 8812-1061) and 9 a separate power chamber discharge, as at 42-44 of FIG. 1, is not required. With the exception of these differences, other structural characteristics of FIG. 1 occur in FIG. and need not be described in detail.

Operation: FIG. 5

Operation here is identical to that of FIG. 1 with the exception of differences brought about by the sealed piston and the omission of the check valve from passage 88b and the further omission of power chamber discharge passage means 42-44. Valve opening is the same as in FIG. 1 (or FIG. 4). When valve 68]] opens, inlet pressure charging power chamber 36a via port 56b also charges valve chamber 84b via passage means 88b90b, following by closing of the valve as before. Valve chamber 84b is then discharged via outlet 106b, also as before. But in this case, the same passage, i.e., 88b-90b-94b- 106b, serves also as the power chamber discharge passage. The same would be true in FIG. 4, if the piston were sealed and check valve 114!) and passage means 42a- 44a omitted. It will be seen that the present vent passage 94b-106b could be eliminated and replaced by a power chamber discharge as at 42-44 of FIG. 1 or 42a- 44a of FIG. 4.

Characteristics of FIG. 5 are these: the seal 39 is apt to prevent air-entrained lubricant from reaching the piston-hammer walls beyond the seal; and power and valve chambers 36b and 8412, respectively, discharge at the same rate. On the other hand, considerable economy is available in that two separate passages and controls need not be provided. For real economy but without control, both outlets 42 (42a)44 (44a) and 106 (106a) could be eliminated along with piston seal 39, reliance being placed on piston-cage leakage for exhaust of both power and valve chambers via 88 (FIG. 1) or 88b (FIG. 4). The characteristics of this have already been covered under FIGS. 1-3.

FIG. 6: Description This figure is a substantial repeat of a portion of FIG. 1, with some of the attributes of FIG. 4, and the suffix c is used on representative numerals. The basic difference from FIGS. 1, 4 and 5 resides in means for admitting air from the inlet chamber to the valve chamber. In FIG. 1, for example, this is accomplished axially of valve 68 when the valve opens and air enters valve passage 88 as it rushes through port 50. In FIG. 5, admission occurs radially of the valve and directly from the inlet chamber.

Representative parts appearing in FIGS. 1 and 4 are piston 30c, inlet chamber 48c, valve housing 620, housing support cup 58c having openings 60c, valve 68c with pressure areas 740 and 860, the latter operating in valve chamber 84c. The valve is, as before, closed by magnetic means as at 780, to block port 560. Valve 680 is without an axial passage as 88 in FIG. 1 but does have bore 900 in which spring 1120 is contained and to which a cross passage 940 in the valve leads from the exterior of the valve.

Valve housing 620 has a pair of axially spaced apart radial passages 88c and 960 and valve 680 carries three annular seals at 87 for purposes to presently appear. Passage 86c leads ultimately to outlet 1060 via passage portions 100a and 102c and needle valve 1040. The power chamber is discharged by a passage 42c which has a control cock, not shown.

Operation: FIG. 6

When valve 68c is closed, its cross passage 960 is in register with valve housing passage 96c and thus valve chamber 860 is vented, here to atmosphere, via outlet 106C, since passage 96c leads there by way of passage portions 100a and 1020. Passage 88c, although open to inlet chamber 48c, is nevertheless blocked by the wall of valve 68c; i.e., passage 880 is out of register with valve passage 94c.

The effect of inlet pressure then rises to a value sufii cient to open the valve, acting on the valve area 740 as before, and air rushes into the power chamber, also as before. Since valve 68c has no central passage like 88 in FIG. 1, and there is no passage like 88a in FIG. 4, there is now no communication between the power chamber and the valve chamber 840. But, the valve chamber is nevertheless charged from the inlet chamber because, as the valve opens, its cross passage 94c moves out of register with housing discharge passage portion 940 and into register with charging passage 880, which is in direct communication with inlet chamber 480. Broadly, as in the other modifications disclosed here, the valve chamber is charged or pressurized by inlet chamber pressure as an incident to valve opening. In the one case, the passage means is eifectuated upon opening of port 56 (56a, 56b) and in the other case by registering passages 94c and 88c; although, the port 56c is also opened for its power-chamber-charging function.

Summary Features of the invention common to all forms thereof will readily suggest other variations. Subsidiary aspects peculiar to fewer than all forms can be easily adapted to others; e.g., the passage means 88a of FIG. 4 could be used in FIG. 1; likewise the passage means 88c of FIG. 6; the remote disposition power and inlet chambers of FIG. 4 could be used in FIG. 1. Omissions and additions among the modifications can be availed of where performance, capacity, cost etc. factors make that desirable. These and other alterations progressing from what is disclosed will readily occur to those versed in the art, all without departure from the spirit and scope of the invention.

What is claimed is:

1. In a vibrator or like apparatus having an elasticfluid-pressurizable inlet chamber connected by means incl-uding a port to a power chamber expansible by inlet pressure via the port and contractable when discharged to a lower pressure to incur movement of a work member respectively on power and return phases, the improvement residing in means for controlling the transmission of fluid pressure in cyclical bursts from the inlet chamber to the power chamber, comprising: a valve and means carrying the valve for movement between portopening and port-closing positions; means releasably holding the valve initially closed and operative to resist valve-opening forces below, and to suddenly release the valve at a predetermined value; means operative by the valve and affording a port-control portion covering the port in the closed position of the valve and presenting a first area exposed to the power chamber exclusively of the inlet chamber and uncovering the port in the open position of the valve and exposed to the effects of inlet chamber pressure in a valve-opening direction; means acting on the valve and presenting a second area exposed to the effects of inlet chamber pressure in a valve opening direction and receivable of the eflfects of inlet chamber pressure to create a valve-opening force at said value for overcoming said releasable means so as to suddenly open the port and thereby pressurizing both areas so as to tend to keep the valve open; and valve-return means combining with the releasable means to effect re-closing of the valve, including means associated with the valve and providing a third chamber additional to the inlet and power chambers, a fluid-pressurizable and -depressurizible third area movable in said third chamber and effective on the valve in opposed relation to said first and second areas, passage means operative when the valve is closed to conduct said third chamber to a pressure lower than inlet chamber pressure so as to enable opening of the valve via said second area and means operative when the valve is open to pressurize said third area, said areas being so constructed relative to each other that the pressure effects on the third area counteract at least in part the pressure effects on the first and second areas that tend to keep the valve open whereby to condition the valve for re-closing.

2. In a vibrator or like apparatus including an elasticfluid-pressurizable inlet chamber connected by means including a port to a power chamber expansible by inlet pressure via the port and contractible when discharged to a lower pressure in accompaniment with movement of a work member respectively in power and return phases, the improvement residing in means for effecting the transmission of inlet chamber pressure to the power chamber in cyclical bursts via the port in alternation with discharge of the power chamber to incur expansion and contraction thereof; comprising valve structure disposed in proximity to the port and including a support and a valve carried by the support for movement between port-opening and port-closing positions, valve opening and closing means including first and second pressure-responsive areas acting in opposite directions on the valve and effective upon changes in pressure differential therebetween to determine the direction of valve movement, a valve chamber separated from the power chamber at least in part by the valve and containing the second area, and means releasably holding the valve closed and operative to resist valve-opening forces below, and to suddenly release the valve at, a predetermined value, said first area being exposed to inlet chamber pressure and eifective when the pressure differential exists in its favor to incur a valve-opening force up to said value for overcoming the releasable means and thus to suddenly open the port and said second area combining with the eifects of the releasable means to effect reclosing of the valve when the pressure differential in favor of the first area is at least partly removed; and valve cycling means operative when the valve is closed to depressurize the valve chamber to a pressure lower than that of the inlet chamber to cause a pressure diiferential to exist in favor of valve opening and operative when the valve opens to connect the valve chamber to the inlet pressure and thus to change the pressure differential in favor of valve closing.

3. The invention defined in claim 2, in which: said valve-opening force is developed by pressurizing of said first area mechanically independently of the work memher.

4. The invention defined in claim 2, in which: said valve cycling means has a passage system which includes a first passage portion leading from the valve chamber to the inlet chamber for pressurizing said second area when the valve is open and a separate second passage portion leading from said valve chamber to said lower pressure and exclusively of the power chamber when the valve is closed.

5. The invention defined in claim 4, in which: the valve includes control portions controlling said passage portions according to the position of the valve.

6. The invention defined in claim 4, in which said first passage portion includes a check valve opening said first passage portion to the eifects of inlet chamber pressure and closing against the discharge of the valve chamber to the power chamber whereby said area is compelled to lead to said lower pressure by said second passage portion.

7. The invention defined in claim 2, including biasing means acting on the valve in a closing direction.

8. The invention defined in claim 2, in which: the releasable means comprises magnetic means.

9. The invention defined in claim 2, in which: the valve and valve support are arranged in coaxial relation to the port and the valve includes a port-control portion constructed to enter and close the port to withdraw from and open said port.

10. The invention defined in claim 9, in which: the port-control portion includes an annular seal cooperative with the interior of the port in the port-closing position of the valve.

11. The invention defined in claim 9, in which: the releasable means includes a plurality of magnets arranged concentrically about the port.

12. The invention defined in claim 2, in which said valve cycling means has a passage system which includes a first passage portion between the inlet and valve chambers for pressurizing said second area when the valve is open, a second passage portion leading to said lower pressure exclusively of the power chamber, and further passage means is provided for discharging the power chamber.

13. The invention defined in claim 12, including separate means for respectively controlling the rates of fluid flow through said second passage portion and said further passage means.

14. The invention defined in claim 2, in which: the valve support is a cylinder having an open end facing toward and axially alined with the port and having an opposite closed end, the valve is a piston slidably carried by and in fluid-tight relation to the cylinder and has at the open end of the cylinder a piston portion providing both a port-control portion and said first area and has at the closed end of the cylinder an end portion affording said second area, and said last-named end of the valve and the closed end of the cylinder provides said valve chamber.

15. The invention defined in claim 2, including: spring means acting in a closing direction on the valve, and means for varying the force of said spring means.

16. The invention defined in claim 2, in which: the valve support is a cylinder having an open end facing the port in coaxiality therewith and an opposite'closed end, the valve is a piston having opposite ends respectively at said open and closed cylinder ends, the valve end at said closed end cooperating therewith to afford said valve chamber and said second area and the valve at its end at the open cylinder end affording a port-control portion and said first area, and the diameter of the valve at its end within said valve chamber being equal to the diameter thereof at its opposite port-proximate end, said port-control portion being of reduced diameter.

17. The invention defined in claim 2, in which: said valve cycling means has a passage system which includes a first passage portion extending through the valve from the first area portion to said second area and a second passage portion leading said valve chamber to said lower pressure, said first passage portion having a check valve openable toward said valve chamber and closable toward said first area portion, a first spring means is contained within the first passage portion to act on the valve in a closing direction and a second spring is also disposed within said first passage portion and biasing the check valve closed.

18. The invention defined in claim 2, including means for adjusting the rate of discharge of the valve chamber so as to regulate the valve-cycling frequency.

19. The invention defined in claim 2, in which the valve cycling means has a passage system which is operative when the valve is closed to depressurize the valve chamber via the contracting power chamber. v

20. The invention defined in claim 2, in which th valve cycling means has a passage portion by means of which the power chamber is contractible when the valve is closed.

21. In a vibrator or like apparatus including an elasticfluid-pressurizible inlet chamber connected by means including a port to a power chamber expansible by inlet pressure via the port and contractible when discharged to a lower pressure in accompaniment with movement of a work member respectively in power and return phases, the improvement residing in means for effecting the transmission of inlet chamber pressure to the power chamber in cyclical bursts via the port in alternation with discharge of the power chamber to incur expansion and contraction thereof; comprising valve structure disposed in proximity to the port and including a support and a valve carried by the support for movement between port-opening and port-closing positions, valve opening and closing means including first and second pressure-responsive areas acting in opposite directions on the valve and effective upon changes in pressure differential therebetween to determine the direction of valve movement, a valve chamber separated from the power chamber at least in part by the valve and containing the second area, and magnetic means releasably holding the valve closed and operative by magnetic attraction and holding forces to resist valve-opening forces below, and to suddenly release the valve at, a predetermined value, whereby the magnetic attraction diminishes, said first area being exposed to inlet chamber pressure and effective when the pressure differential exists in its favor to incur a valve-opening force up to said value for overcoming the magnetic holding force and thus to suddenly open the port and to move the valve in an amount where the magnetic attraction is relatively weak and said second area combining with the magnetic attraction to return the valve in an amount within the range of stronger magnetic attractive forces to effect reclosing of the valve when the pressure differential in favor of the first area is at least partly removed; and valve cycling means operative when the valve closes to discharge the valve chamber to a pressure lower than that of the inlet chamber to cause a pressure differential to exist in favor of valve opening and operative when the valve opens to connect the valve chamber to the inlet chamber and thus 14 to change the pressure differential in favor of valve closmg.

22. The invention defined in claim 2, in which: said valve cycling means has a passage system which includes a first passage portion leading from the valve chamber to the inlet chamber for pressurizing said second area when the valve is open and a separate second passage portion leading from said valve chamber to said lower pressure, a check valve opening said first passage portion to the effects of inlet chamber pressure and closing against the discharge of the valve chamber to the power chamber whereby said area is compelled to lead to said lower pressure by said second passage portion, the releasable means comprises magnetic means, and biasing means acts on the valve in a closing direction when the valve is open.

References Cited by the Examiner UNITED STATES PATENTS 1,062,749 5 13 Townsend 91-50 2,667,895 2/54 Pool 25165 2,707,940 5 Harris 913 18 2,996,071 8/61 Takoka 251- 3,088,440 5/63 Wilmer 173-121 SAMUEL LEVINE, Primary Examiner.

FRED E. ENGELTHALER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,216,328 November 9, 1965 Axel H. Peterson certified that error appears in the above numbered pat- It is hereby rection and that the said Letters Patent should read as ent requiring cor corrected below.

Column 5, line 44, for 700" read .700

Signed and sealed this 17th day of May 1966.

(SEAL) Attest: ERNEST W. SWIDER EDWARD J. BRENNER Commissioner of Patents Attesting Officer 

1. IN A VIBRATOR OR LIKE APPARATUS HAVING AN ELASTICFLUID-PRESSURIZABLE INLET CHAMBER CONNECTED BY MEANS INCLUDING A PORT TO A POWER CHAMBER EXPANSIBLE BY INLET PRESSURE VIA THE PORT AND CONTRACTABLE WHEN DISCHARGED TO A LOWER PRESSURE TO INCUR MOVEMENT OF A WORK MEMBER RESPECTIVELY ON POWER AND RETURN PHASES, THE IMPROVEMENT RESIDING IN MEANS FOR CONTROLLING THE TRANSMISSION OF FLUID PRESSURE IN CYCLICAL BURSTS FROM THE INLET CHAMBER TO THE POWER CHAMBER, COMPRISING: A VALVE AND MEANS CARRYING THE VALVE FOR MOVEMENT BETWEEN PORTOPENING AND PORT-CLOSING POSITIONS; MEANS RELEASABLY HOLDING THE VALVE INITIALLY CLOSED AND OPERATIVE TO RESIST VALVE-OPENING FORCES BELOW, AND TO SUDDENLY RELEASE THE VALVE AT A PREDETERMINED VALUE; MEANS OPERATIVE BY THE VALVE AND AFFORDING A PORT-CONTROL PORTION COVERING THE PORT IN THE CLOSED POSITION OF THE VALVE AND PRESENTING A FIRST AREA EXPOSED TO THE POWER CHAMBER EXCLUSIVELY OF THE INLET CHAMBER AND UNCOVERING THE PORT IN THE OPEN POSITION OF THE VALVE AND EXPOSED TO THE EFFECTS OF INLET CHAMBER PRESSURE IN A VALVE-OPENING DIRECTION; MEANS ACTING ON THE VALVE AND PRESENTING A SECOND AREA EXPOSED TO THE EFFECTS OF INLET CHAMBER PRESSURE IN A VALVE OPENING DIRECTION AND RECEIVABLE OF THE EFFECTS OF INLET CHAMBER PRESSURE TO CREATE A VALVE-OPENING FORCE AT SAID VALUE FOR OVERCOMING SAID RELEASABLE MEANS SO AS TO SUDDENLY OPEN THE PORT AND THEREBY PRESSURIZING BOTH AREAS SO AS TO TEND TO KEEP THE VALVE OPEN; AND VALVE-RETURN MEANS COMBINING WITH THE RELEASABLE MEANS TO EFFECT RE-CLOSING OF THE VALVE, INCLUDING MEANS ASSOCIATED WITH THE VALVE AND PROVIDING A THIRD CHAMBER ADDITIONAL TO THE INLET AND POWER CHAMBERS, A FLUID-PRESSURIZABLE AND -DEPRESSURIZABLE THIRD AREA MOVABLE IN SAID THIRD CHAMBER AND EFFECTIVE ON THE VALVE IN OPPOSED RELATION TO SAID FIRST AND SECOND AREAS, PASSAGE MEANS OPERATIVE WHEN THE VALVE IS CLOSED TO CONDUCT SAID THIRD CHAMBER TO A PRESSURE LOWER THAN INLET CHAMBER PRESSURE SO AS TO ENABLE OPENING OF THE VALVE VIA SAID SECOND AREA AND MEANS OPERATIVE WHEN THE VALVE IS OPEN TO PRESSURIZE SAID THIRD AREA, SAID AREAS BEING SO CONSTRUCTED RELATIVE TO EACH OTHER THAT THE PRESSURE EFFECTS ON THE THIRD AREA COUNTERACT AT LEAST IN PART THE PRESSURE EFFECTS ON THE FIRST AND SECOND ARES THAT TEND TO KEEP THE VALVE OPEN WHEREBY TO CONDITION THE VALVE FOR RE-CLOSING. 